Cross-country ski

ABSTRACT

Cross-country ski ( 1 ) having a tip ( 4 ) curved upward, extending beyond the front contact line ( 2 ), wherein the projection of the side line of the tip ( 4 ) of the ski over a horizontal plane has an inflexion point ( 6, 7 ) located forward of the front contact line ( 2 ), at least on one side of the ski.

TECHNICAL FIELD

[0001] The invention relates to the field of gliding sports and, moreparticularly, to that of cross-country skiing. More precisely, itrelates to a cross-country ski having a tip that is optimized and, moreprecisely, “narrowed” in comparison to conventional cross-country skis.

Prior Art

[0002] In a known manner, a cross-country ski has a front end forming atip. This tip forms an upwardly curved zone, the width of whichdecreases toward its end. This tip is curved upward to enable the ski tobe on top of the snow and to overcome obstacles and differences in levelthat exist on the gliding trail.

[0003] Generally speaking, this tip is considered to start forward of atransverse line defined in standard fashion as the front contact line.

[0004] In cross-country skiing specifically, using the skatingtechnique, the skier performs a movement in which the bearing forces aretaken up while the ski is oriented obliquely relative to the directionof displacement.

[0005] After having exerted a bearing force on one of the skis, theskier raises this ski so as to bring it forward while he slides on theother ski.

[0006] In point of fact, it is frequently observed that, when the skierraises his ski while he slides on the other, the tip tends to come intofrictional contact against the snow. When the tip scrapes the snow inthis way, it disrupts the skier's movement by reducing his efficiencyand, in certain cases, even risks causing him to fall.

[0007] The object of the invention is to eliminate or at the very leastgreatly reduce these scraping effects of the tip, which skiers commonlycall “snow-shovel” effects.

SUMMARY OF THE INVENTION

[0008] The invention therefore relates to a cross-country ski having atip extending beyond the front contact line.

[0009] According to the invention, the projection of the side line ofthe tip of the ski over a horizontal plane has an inflection pointlocated forward of the front contact line, at least on one side of theski.

[0010] In other words, the invention consists in reducing the width ofthe tip in comparison to existing skis, by “narrowing” it. Thus, forwardof the front contact line, the ski has a marked narrowing, forming aninflexion point on its side line when the latter is observed from above.Beyond this inflexion point, the tip has a width that decreases lessseverely up to the end of the ski.

[0011] Thus, the tip has a relatively marked variation in its widthbeyond the front contact line.

[0012] In practice, this width reduction may be located at least on theinner side of the ski when the right and left skis are different.Nevertheless, more generally, as skis are usually symmetrical, thiswidth reduction may also be symmetrical relative to the medianlongitudinal plane, the tip in this case having two inflexion points,one on either side of the ski.

[0013] Because the side line at the tip is offset toward the medianlongitudinal plane of the ski, relative to the side line forming theedges, the risks of seeing this tip scrape the snow when the skierbrings his ski forward are greatly reduced.

[0014] This result of better “skiability” is combined with a slightreduction in the weight of the ski tip and thus of the ski, which givesrise to a reduction in the ski's overall inertia. This combinationimproves the ski's behavior.

[0015] In practice, it was observed that the effects sought weresatisfactory when the width of the tip measured midway between the endof the tip and the front contact line is between 40 and 80%, preferablybetween 50 and 75%, of the width measured in the region of the frontcontact line.

BRIEF DESCRIPTION OF THE FIGURES

[0016] The way in which the invention is implemented and also theadvantages arising therefrom will become clearly apparent from thedescription of the embodiment that follows, based on the appendedfigures, in which:

[0017]FIG. 1 is a side view of a cross-country ski according to theinvention;

[0018]FIG. 2 is a top view of the ski in FIG. 1.

IMPLEMENTATION OF THE INVENTION

[0019] The front of the cross-country ski (1) shown in FIG. 1 lies in ahorizontal plane H. The front contact line (2) illustrated in FIG. 1corresponds to the longitudinal level of the ski where the sole (3)ceases to be in contact with the horizontal plane H. The tip startsbeyond this front contact line (2). This tip is curved upward as far asits end (5).

[0020] According to the invention, and as illustrated in FIG. 2, the tip(4) has two inflexion points (6, 7) located on either side of the medianlongitudinal plane (8). More precisely, these inflexion points occur onthe projection of the side line of the tip (4) over the horizontal planeon which the sole (3) lies.

[0021] The inflexion point is understood in its geometrical definitionas the point (6, 7) where the side line of the tip (4) crosses itstangent (15). Thus, to the rear of the inflexion point (6, 7), theportion (10, 11) of the side line has a curve oriented toward the insideof the ski. Conversely, forward of this inflexion point (6, 7) , theportion (12, 13) of the side line has a curve oriented toward theoutside.

[0022] Therefore, the tip (4) has a narrowing of its width that moves itaway from the profile (16, 17) shown in dotted lines in FIG. 2,corresponding to the extension of the side line (18, 19) to the rear ofthe front contact line 2.

[0023] In the embodiment illustrated, the two inflexion points (6, 7)are located at the same longitudinal level, but in other variantembodiments that are not shown they may be offset longitudinally and belocated closer to or farther away from the front contact line.

[0024] In practice, and by way of example, the width L of the board inthe region of the front contact line (2) is of the order of 38millimeters. The width l, measured in a horizontal plane midway betweenthe projection (9) of the end (5) of the tip (4) and the front contactline (2) is of the order of 26 millimetres.

[0025] It emerges from the foregoing that the cross-country skiaccording to the invention has several advantages owing to the narrowingof its tip. Particular mention may be made of the quasi-elimination ofthe risk of scraping the snow in the region of the tip during themovements to bring the ski forward when skating. Mention will also bemade of a slight reduction in the weight of the tip of the ski, andtherefore of the ski, which gives rise to a reduction in the ski'soverall inertia, which improves its behavior.

1. A cross-country ski (1) having a tip (4) curved upward, extendingbeyond the front contact line (2), wherein the projection of the sideline of the tip (4) of the ski over a horizontal plane H has aninflexion point (6, 7) located forward of the front contact line (2), atleast on one side of the ski.
 2. The ski as claimed in claim 1, whereinthe projection of the side line of the tip (4) of the ski over ahorizontal plane has two inflection points (6, 7) located forward of thefront contact line, on each side of the ski.
 3. The ski as claimed inclaim 2, which is symmetrical relative to its median longitudinal plane,at least in its tip zone.
 4. The ski as claimed in claim 3, wherein thewidth l of the tip (4) measured midway between the end (5) of the tip(4) and the front contact line (2) is between 40 and 8%, preferablybetween 50 and 75%, of the width L measured in the region of the frontcontact line 2.